Nitrogen → 3-Fluoropyridine-2-sulfonamide

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Reaction Steps

5.3 g (0.030 mol) of 3-aminopyridin-2-ylsulfonamide are dissolved in 12 ml of dimethyl sulfoxide, and the solution is added dropwise at 0° C. to 14.3 g (0.72 mol) of hydrogen fluoride (exothermal reaction). 2.4 g (0.035 mol) of sodium nitrite are then added in portions at 0° C. After one hour, the mixture is heated to 70° C. (evolution of N2). After the reaction mixture has cooled, it is added to an ice/water mixture, sodium bicarbonate and sodium chloride are added, and the mixture is then extracted with tetrahydrofuran and ethyl acetate. The combined extracts are washed with a saturated sodium chloride solution, dried with magnesium sulfate, filtered and evaporated. The residue is stirred in diethyl ether/petroleum ether. Filtration gives 3.7 g of 3-fluoropyridin-2-ylsulfonamide (Compound No. 3.001) of a melting point of +124° to +125° C.

Provenance & Evidence